For NAND flash memories, there are specifications for externally changing the settings of memory internal states, such as an output buffer size and operation mode selection. A process for issuing a command for changing the settings of memory internal states in accordance with the specifications and executing the command is called as a set feature command sequence.
There is a tendency for NAND flash memories that, as the memory capacity increases, the number of setting-change allowable states increases. Information on a state for which a setting change has been instructed by a set feature command is stored in a register in a memory. Therefore, as the number of setting-change allowable states increases, the number of registers has to be increased, which results in increase of the memory chip area.